Blog post #8: A Matter of Selection (Grace Slone)

Over many months of observing and monitoring the growth of our Brassica oleracea plant,

there are many things that have become known. However, Brassica oleracea has not stayed

the same for all of its existence on earth. It has changed, adapted, and gone through a process

called natural selection in order to form new variations of the same species. The part of the plant

that I decided to observe were the leaves of the plant. I noticed that the leaves in the various

plants had a range in width from 1.5 cm to 16 cm. I also noticed that the leaves in the plants

had a range in length from 6 cm to 24 cm. These two facts prove that compared to other parts

of the plant, the leaves have the greatest variation and depend mostly on what type of

Brassica oleracea plant it is.

I think that there is so much variation in Brassica oleracea because over time, as the plants have been

planted in various locations, they have needed to adapt to their new environments, and in turn have

developed new traits. However, upon the human discovering of these plants, we have genetically used

selective breeding in order to produce a plant that is able to be consumed by humans. It is also through

artificial selection to allow for certain traits to show in these plants. Another way that these plants have

become so different is through mutations in the genes which then gets passed on and on and as a result

forms a new variation. Descent with modification also plays a role in this variation because without

passing from parent to offspring, there would be no way the traits to become a new variation.

The part of the plant that I noticed had very little variation was the texture of the leaves. This may be
because they all serve the same function of repelling water off of the plant. I think this because without a
little similarity, they would not be able to breed with one another and produce fertile offspring. Scientists
would have to modify the gene in the plant which coded for the texture of the plant’s leaves to be a
certain texture. However, if the option of genetically modifying was not an option, which it is very
expensive and complicated, the more logical option would be to manually fertilize each plant. In
order for this to occur, pollen would need to be on the stigma of the flower and travel down into the
ovary in order to form a new seed. This would not be taking the exact desired genes, however, if a
plant had a gene that you wished to have an extreme of a certain phenotype, you would have to continue
to breed the offspring of the first plant. Over time, this would result in differentiation and possibly even a
new variation of a species.

Leaf
Width	16 cm	14 cm	10 cm	1.5 cm	8 cm	14 cm	8 cm	14 cm	8 cm
Length	19 cm	24 cm	14 cm	6 cm	6 cm	9 cm	22 cm	19 cm	11 cm
Edge	Ruffled	Ragged	Ragged	Spiked	Smooth	Ragged	Ragged	Ragged	Ragged
Texture	Bumpy	Bumpy	Bumpy	Smooth	Smooth	Smooth	Smooth/bumpy (mix)	Smooth/bumpy (mix)	Smooth/ bumpy (mix)